"You came home…"
I would use ἥκεις for this; it's technically a present-tense verb, but it generally has a perfect meaning, "you have come back". If you want to be emphatic, add πάλιν, "…back again".
EDIT: Brianpck in the comments suggested an even better verb, ἐνοστήσας, "you came back home". I'd recommend this one instead of my original suggestion. It comes from the word νόστος "journey home", as made famous in the Odyssey, and the root of "nostalgia".
"…to our hearts…"
I'd leave off "our" and just go with εἰς τὰς καρδίας; the definite article can give that sense on its own. If you want to include the "our", that's ἐις τὰς ἡμετέρας καρδίας.
"…with your shield."
Nice and straightforward, σὺν τῇ ασπίδι. Once again, leaving off the non-emphatic "your".
All in all, ἐνοστήσας σὺν τῇ ασπίδι ἐις τὰς ἡμετέρας καρδίας. You can reorder the words pretty freely in order to get the effect you want, too.
Note: I'm not entirely certain about using σύν like this. I might instead use a participle, something like "…holding your shield". But that's somewhat of a change in meaning.